I sort of lean towards wildflowerchild's response, but as Guinness suggests, a psychiatrist is the best person to confirm any diagnosis, or lack thereof.

People can lack insight to hypomania, and even mania. However, the DSM-5, in the US, clearly states that even hypomania is generally noticable to others and clearly reflects a difference from a person's stable state. Hypomanic symptoms are also ones that others can usually identify as "Yea, so-and-so does talk fast" or "Yea, they can act a little wild, or strange, or over-the-top on occasion or seem to do a lot more than most people sometimes." Of course there are people without bipolar that are loud Chatty Cathys and/or high energy wild childs, but they may not exhibit any major changes to that state under normal circumstances.

Have you ever heard of the Bipolar Spectrum? Some experts have a very broad definition of it, while others don't. Some that do may even consider a person whose moods frequently fluctuate between mild to moderate depression and stable baseline as on the spectrum. Such a person may not necessarily qualify for even a bipolar 2 or Cyclothymia diagnosis, but may still benefit from bipolar moodstabilizers more than antidepressants.

I don't know if you are female or male, but in some cases hormonal issues could be in play. Or something totally different unrelated to mental illness. I only mention this because these issues and questions are the reasons why diagnosis by a psychiatrist is recommended.